Vice President Joe Biden (l.), accompanied by New York Mayor Michael Bloomberg, speaks in New York's City Hall Blue Room on Thursday. Relatives of shooting victims from Newtown, Conn., stood with Mayor Bloomberg and Vice President Biden as they spoke in favor of an assault weapons ban.

Washington — For the second day in a row, Vice President Joe Biden made an emotional plea for gun-control legislation – including an assault weapons ban that Senate majority leader Harry Reid has already removed from the bill, saying it can’t pass.

Speaking Thursday alongside Michael Bloomberg, New York mayor and antigun activist, Vice President Biden asserted that some of the victims of last December’s Newtown, Conn., massacre might be alive today had those restrictions been in place.

“For all those who say we shouldn't and can't ban assault weapons, for all those who say the politics is too hard,” Biden said at City Hall in New York, accompanied also by parents of Newtown victims, “how can they say that when you take a look at those 20 beautiful babies and what happened to them and those six teachers and administrators?”

“We are still pushing that it pass,” said Biden, a former senator. “The same thing was told to me when the first assault weapons ban in 1994 was attached to the Biden crime bill – that it couldn’t possibly pass.”

The ban did eventually pass, and was in place for 10 years, before it expired in 2004.

But why is Biden still pushing so hard for something the top Democrat in the Senate says can’t pass, and will not be part of the gun-control package that goes before Congress after the Easter recess? Senator Reid said Tuesday the assault weapons ban didn’t even have 40 votes, out of 60 needed to overcome a filibuster.

Three reasons:

Biden is the head of President Obama’s gun-control task force, he feels strongly about the issue, and there’s no downside to pushing for an assault-weapons ban until the bitter end. By insisting it can still pass – which surely he knows isn’t true – he is providing cover for the other parts of the package. Reid has not revealed what will be in the final version, but the elements include: expanded background checks on gun purchasers, limits on the size of ammunition magazines, new restrictions on gun trafficking, and money for school safety.

Biden is also speaking to the base of the Democratic Party, which is upset that Reid (and by extension, Mr. Obama) gave up without a vote. Included in that base is Sen. Dianne Feinstein (D) of California, author of the original assault-weapons ban. Biden is honoring her passion and history on the gun issue. Senator Feinstein was the president of the San Francisco Board of Supervisors in 1978 when the mayor and city administrator were assassinated – a scene she discovered after hearing the gunshots.

Biden is contemplating a run for the presidency in 2016, and wants to keep Democratic activists happy for his own purposes.

White House chief of staff Denis McDonough said Tuesday that Feinstein could still get her vote by bringing up the assault-weapons ban as an amendment to another bill.

“We’re going to work on this, we’re going to find the votes, and it deserves a vote,” Mr. McDonough said on CNN. “Let’s see if we can get it done.”